GM Releases 2013 bogus HP ratings at PRI show

[Greg Hill]

Originally Posted by Andrew Hill

This head is the part number listed in the engine blueprint guide
M-6049-Z304DA

http://www.roushyatesparts.com/ford-...049-z304da.htm

it talks about CNC porting at the bottom, so the accepted head is the non-CNC'd version?

There's something screwy in this head deal because Roush says the heads have runner volumes of 204 and 85 as cast and the spec in the engine blueprint section says 230 and 91. Wonder where those extra cc's came from?